| 1. |
- Arinaitwe, Evalyne, et al.
(author)
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Is the fire performance of phase change materials a significant barrier to implementation in building applications?
- 2024
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In: Journal of Energy Storage. - : Elsevier. - 2352-152X .- 2352-1538. ; 94
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Journal article (peer-reviewed)abstract
- This paper examines the reaction-to-fire behaviour of building materials containing phase change materials by predicting their fire classification according to the European reaction-to-fire classification system (Euroclasses). While various building materials containing PCMs exist today, their application in buildings has been somewhat limited due to the fire behaviour of these building materials. Existing research has focused on small scale testing which does not allow determination of the Euroclass of the material. In this application, large scale performance is predicted based on previously published small scale data to provide some valuable insights into the expected fire performance of these materials. As a starting point, a systematic literature review on phase change materials (PCM) and fire behaviour was conducted, with the purpose of identifying all existing literature concerning experimental investigation of the fire behaviour of building materials containing PCMs. In total, 816 articles were selected from the literature search. After screening of these papers, 51 articles were fully reviewed and included in the next step of the study. In the next step, the reaction-to-fire behaviour of the building materials with PCMs that were identified from the literature was predicted using the ConeTools simulation program. The input data required for ConeTools was obtained from the identified literature. Initially, 27 of the 51 studies used cone calorimetry as a fire testing method and could therefore be considered for the Euroclass assessment. However, of the 27 studies, only 17 studies provided information on both the heat release rates (HRR) and time to ignition (TTI) and were selected for use in the ConeTools program. The ConeTools program predicted Euroclasses for all the building materials containing PCMs from the selected 17 studies. The predicted Euroclasses for most materials was low (i.e. fire classes ‘D' or ‘E or worse') which confirms that materials containing PCMs generally have a low react-to-fire behaviour even with addition of flame retardants (FR). Our findings indicate that the fire behaviour, typically Euroclass ‘D' or ‘E or worse', of the building materials containing PCMs is indeed a barrier to their implementation in the building applications where Euroclass C or higher is required, e.g. in evacuation pathways or certain public spaces. The predictions of the Euroclasses based on ConeTools need to be confirmed using Single Burning Item tests (EN 13823) and/or Room Corner tests (ISO 9705) in the future, to enable a better understanding of fire behaviour of these building materials.
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| 2. |
- Bamgbopa, Musbaudeen O., et al.
(author)
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Towards eco-friendly redox flow batteries with all bio-sourced cell components
- 2022
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In: Journal of Energy Storage. - : ELSEVIER. - 2352-152X .- 2352-1538. ; 50
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Research review (peer-reviewed)abstract
- Recent research and few pilot deployments have demonstrated promising aqueous organic redox flow battery (RFB) systems. However, the claim that these organic RFB systems are eco-friendlier energy storage than Lithium-ion batteries and aqueous inorganic metallic RFB counterparts needs reinforcement, primarily if cell components other than redox-active species are still based on unsustainable materials. This thesis of the present work presents the prospects of achieving future eco-friendly RFBs with higher consideration for sustainability by adopting significant amounts of abundant bio-sourced/based materials for all main cell components. As we highlight the promising sources of the energy materials from a review of previous studies, we infer that plant derived quinones and other organic polymers may continue to dominate the organic redox-active species space. Furthermore, a candidate methodology to accomplish porous electrodes and membranes/separators of the eco-friendly RFBs is to apply stand-alone bio-based/sourced fibrils derived from cellulose, lignin, chitin, among other materials. These materials can be combined with (un)carbonised biomass or food wastes & residues to impart conductivity, catalytic activity, and ion selectivity. We explore symmetric chemistry as an ideal system for the eco-friendly RFBs of the discourse, given interplay between the electrolyte, electrode material and membrane dictates energy efficiency and cycling stability. These strategies also need to be coupled with further improvements to achieve reliability.
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| 3. |
- Behi, Hamidreza, et al.
(author)
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Thermal management analysis using heat pipe in the high current discharging of lithium-ion battery in electric vehicles
- 2020
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In: Journal of Energy Storage. - : Elsevier Ltd. - 2352-152X .- 2352-1538. ; 32
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Journal article (peer-reviewed)abstract
- Thermal management system (TMS) for commonly used lithium-ion (Li-ion) batteries is an essential requirement in electric vehicle operation due to the excessive heat generation of these batteries during fast charging/discharging. In the current study, a thermal model of lithium-titanate (LTO) cell and three cooling strategies comprising natural air cooling, forced fluid cooling, and a flat heat pipe-assisted method is proposed experimentally. A new thermal analysis of the single battery cell is conducted to identify the most critical zone of the cell in terms of heat generation. This analysis allowed us to maximize heat dissipation with only one heat pipe mounted on the vital region. For further evaluation of the proposed strategies, a computational fluid dynamic (CFD) model is built in COMSOL Multiphysics® and validated with surface temperature profile along the heat pipe and cell. For real applications, a numerical optimization computation is also conducted in the module level to investigate the cooling capacity of the liquid cooling system and liquid cooling system embedded heat pipe (LCHP). The results show that the single heat pipe provided up to 29.1% of the required cooling load in the 8C discharging rate. Moreover, in the module level, the liquid cooling system and LCHP show better performance compared with natural air cooling while reducing the module temperature by 29.9% and 32.6%, respectively.
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| 4. |
- Behzadi, A., et al.
(author)
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Advanced smart HVAC system utilizing borehole thermal energy storage : Detailed analysis of a Uppsala case study focused on the deep green cooling innovation
- 2024
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In: Journal of Energy Storage. - : Elsevier Ltd. - 2352-152X .- 2352-1538. ; 99
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Journal article (peer-reviewed)abstract
- This article presents and thoroughly examines an innovative, practical, cost-effective, and energy-efficient smart heating, ventilation, and air conditioning (HVAC) system. The fundamental component of this concept is a state-of-the-art method called Deep Green Cooling technology, which uses deep drilling to utilize the ground's heating and cooling potential directly without the need for machinery or heat pumps. This method satisfies demands with the least energy use, environmental impact, and operational costs. In order to effectively oversee and regulate energy production, storage, and utilization, the system consists of an intelligent control unit with many smart controllers and valves. Renewable energy deployment is made easier, and the intelligent automation unit is more compatible with the help of a high-temperature cooling resource with a high supply temperature of 16 °C. The technical, environmental, and financial aspects of the suggested smart office building system in the southern region of Uppsala, Sweden, are evaluated using TRNSYS software. According to the results, boreholes provide more than 28.5 % of the building's energy requirements by utilizing the ground's ability to generate affordable, dependable seasonal thermal energy. The district heating network satisfies the remaining demand, amounting to 787.2 MWh, highlighting the benefits of combining conventional and renewable energy sources for increased supply security and dependability. The borehole thermal energy storage system meets the building's entire cooling need, underscoring the importance of high-temperature cooling systems. The most expensive part of the system is the borehole thermal energy storage, which accounts for over half of the total investment. The system has an appropriate payback period of ten years, proving its long-term profitability and cost-effectiveness, thanks to removing the machinery and heat pump. With 3138 MWh of ground-source heating and cooling, the system saves 17,962 USD by reducing CO2 emissions by about 143.7 t, sufficient to grow 16.3 ha of trees throughout the payback period.
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| 5. |
- Behzadi, Amirmohammad, et al.
(author)
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An efficient renewable hybridization based on hydrogen storage for peak demand reduction : A rule-based energy control and optimization using machine learning techniques
- 2023
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In: Journal of Energy Storage. - : Elsevier Ltd. - 2352-152X .- 2352-1538. ; 57
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Journal article (peer-reviewed)abstract
- The present study proposes and thoroughly examines a novel approach for the effective hybridization of solar and wind sources based on hydrogen storage to increase grid stability and lower peak load. The parabolic trough collector, vanadium chloride thermochemical cycle, hydrogen storage tank, alkaline fuel cells, thermal energy storage, and absorption chiller make up the suggested smart system. Additionally, the proposed system includes a wind turbine to power the electrolyzer unit and minimize the size of the solar system. A rule-based control technique establishes an intelligent two-way connection with energy networks to compensate for the energy expenses throughout the year. The transient system simulation (TRNSYS) tool and the engineering equation solver program are used to conduct a comprehensive techno-economic-environmental assessment of a Swedish residential building. A four-objective optimization utilizing MATLAB based on the grey wolf algorithm coupled with an artificial neural network is used to determine the best trade-off between the indicators. According to the results, the primary energy saving, carbon dioxide reduction rate, overall cost, and purchased energy are 80.6 %, 219 %, 14.8 $/h, and 24.9 MWh at optimal conditions. From the scatter distribution, it can be concluded that fuel cell voltage and collector length should be maintained at their lowest domain and the electrode area is an ineffective parameter. The suggested renewable-driven smart system can provide for the building's needs for 70 % of the year and sell excess production to the local energy network, making it a feasible alternative. Solar energy is far less effective in storing hydrogen over the winter than wind energy, demonstrating the benefits of combining renewable energy sources to fulfill demand. By lowering CO2 emissions by 61,758 kg, it is predicted that the recommended smart renewable system might save 7719 $ in environmental costs, equivalent to 6.9 ha of new reforestation.
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| 6. |
- Belaineh Yilma, Dagmawi, et al.
(author)
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Printable carbon-based supercapacitors reinforced with cellulose and conductive polymers
- 2022
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In: Journal of Energy Storage. - : Elsevier Ltd. - 2352-152X .- 2352-1538. ; 50
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Journal article (peer-reviewed)abstract
- Sustainable electrical energy storage is one of the most important scientific endeavors of this century. Battery and supercapacitor technologies are here crucial, but typically the current state of the art suffers from either lack of large-scale production possibilities, sustainability or insufficient performance and hence cannot match growing demands in society. Paper and cellulosic materials are mature scalable templates for industrial roll-to-roll production. Organic materials, such as conducting polymers, and carbon derivatives are materials that can be synthesized or derived from abundant sources. Here, we report the combination of cellulose, PEDOT:PSS and carbon derivatives for bulk supercapacitor electrodes adapted for printed electronics. Cellulose provides a mesoscopic mesh for the organization of the active ingredients. Furthermore, the PEDOT:PSS in combination with carbon provides superior device characteristics when comparing to the previously standard combination of activated carbon and carbon black. PEDOT:PSS acts as a mixed ion-electron conducting glue, which physically binds activated carbon particles together, while at the same time facilitating swift transport of both electrons and ions. A surprisingly small amount (10%) of PEDOT:PSS is needed to achieve an optimal performance. This work shows that cellulose added to PEDOT:PSS-carbon enables high-performing, mechanically stable, printed supercapacitor electrodes using a combination of printing methods.
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| 7. |
- Bessman, Alexander, et al.
(author)
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Aging effects of AC harmonics on lithium-ion cells
- 2019
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In: Journal of Energy Storage. - : Elsevier. - 2352-152X .- 2352-1538. ; 21, s. 741-749
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Journal article (peer-reviewed)abstract
- With the vehicle industry poised to take the step into the era of electric vehicles, concerns have been raised that AC harmonics arising from switching of power electronics and harmonics in electric machinery may damage the battery. In light of this, we have studied the effect of several different frequencies on the aging of 28 Ah commercial NMC/graphite prismatic lithium-ion battery cells. The tested frequencies are 1 Hz, 100 Hz, and 1 kHz, all with a peak amplitude of 21 A. Both the effect on cycled cells and calendar aged cells is tested. The cycled cells are cycled at a rate of 1C:1C, i.e., 28 A during both charging and discharging, with the exception of a period of constant voltage at the end of every charge. After running for one year, the cycled cells have completed approximately 2000 cycles. The cells are characterized periodically to follow how their capacities and power capabilities evolve. After completion of the test about 80% of the initial capacity remained and no increase in resistance was observed. No negative effect on either capacity fade or power fade is observed in this study, and no difference in aging mechanism is detected when using non-invasive electrochemical methods of post mortem investigation.
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| 8. |
- Björklund, Erik, et al.
(author)
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Influence of state-of-charge in commercial LiNi0.33Mn0.33Co0.33O2/LiMn2O4-graphite cells analyzed by synchrotron-based photoelectron spectroscopy
- 2018
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In: Journal of Energy Storage. - : Elsevier BV. - 2352-152X .- 2352-1538. ; 15, s. 172-180
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Journal article (peer-reviewed)abstract
- Degradation mechanisms in 26 Ah commercial Li-ion battery cells comprising graphite as the negative electrode and mixed metal oxide of LiMn 2 O 4 (LMO) and LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC) as the positive electrode are here investigated utilising extensive cycling at two different state-of-charge (SOC) ranges, 10–20% and 60–70%, as well as post-mortem analysis. To better analyze these mechanisms electrochemically, the cells were after long-term cycling reassembled into laboratory scale “half-cells” using lithium metal as the negative electrode, and thereafter cycled at different rates corresponding to 0.025 mA/cm 2 and 0.754 mA/cm 2 . The electrodes were also analyzed by synchrotron-based hard x-ray photoelectron spectroscopy (HAXPES) using two different excitation energies to determine the chemical composition of the interfacial layers formed at different depth on the respective electrodes. It was found from the extensive cycling that the cycle life was shorter for the cell cycled in the higher SOC range, 60–70%, which is correlated to findings of an increased cell resistance and thickness of the SEI layer in the graphite electrode as well as manganese dissolution from the positive electrode.
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| 9. |
- Brooke, Robert, 1989-, et al.
(author)
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Large-scale paper supercapacitors on demand
- 2022
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In: Journal of Energy Storage. - : Elsevier Ltd. - 2352-152X .- 2352-1538. ; 50
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Journal article (peer-reviewed)abstract
- Clean, sustainable electrical energy could be the next greatest challenge and opportunity of mankind. While the creation of clean energy has been proven, the storage of such energy requires much more research and development. Battery and energy storage technology today relies heavily on rare metals which cannot support large production needs of society. Therefore, the need for energy storage technology to be created sustainably is of great importance. Recently, conductive polymers, a class of organic materials, have shown impressive results in energy storage but requires further development if this technology is to be implemented in various energy storage applications. Here, we report a new ‘on demand’ design for supercapacitors that allows for individual devices in addition to devices in parallel and in series to increase the capacitance and voltage, respectively. The individual device showed impressive capacity up to 10 F while increasing the area with the large parallel device increased the capacitance to a record 127.8 F (332.8 mF/cm2). The ‘on demand’ design also allows paper supercapacitors to be in series to increase the operating voltage with an example device showing good charging behavior up to 5 V when 4 individual paper supercapacitors were arranged in series. Finally, the paper supercapacitors were incorporated into a prototype titled: ‘Norrkoping Starry Night’ which bridges the gap between art and science. An all-printed electrochromic display showing the city of Norrkoping, Sweden, complete with a touch sensor as an on/off switch and silicon solar cells to charge the paper supercapacitors is presented to bring several printed technologies together, highlighting the possibilities of the new paper supercapacitors within this report. © 2022
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| 10. |
- Börjesson Axén, Jenny, et al.
(author)
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Evaluation of hysteresis expressions in a lumped voltage prediction model of a NiMH battery system in stationary storage applications
- 2022
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In: Journal of Energy Storage. - : Elsevier BV. - 2352-152X .- 2352-1538. ; 48, s. 103985-
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Journal article (peer-reviewed)abstract
- As a part of battery system operation, battery models are often used to determine battery characteristics such as the state of charge (SOC) and the state of health (SOH). A phenomenon that has a large impact on battery model accuracy for NiMH batteries is open circuit voltage (OCV) hysteresis, which causes the OCV to differ not only with the SOC of the battery but also with the charge-discharge history. This characteristic is especially influential when running the system in applications with dynamic current patterns. A model including a way to emulate battery hysteresis behavior would improve the battery management system function. In this study a lumped battery model for cell voltage prediction was expanded to include an OCV hysteresis model. Different expressions to describe the hysteresis behavior were explored. The different models were then evaluated using both synthetic and real-life application experimental data. In all cases the error was reduced by adding a hysteresis component to the model. Using this type of model in the battery management system of stationary energy storage systems based on NiMH batteries could help make the state prediction more accurate. This, in turn, would allow for better optimization of the system operation, something that could help increase system efficiency and lifetime.
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